Accommodation of mobility aids, such as wheelchairs, in public transit vehicles is now commonplace. For the convenience of all of the passengers, methods and equipment have been developed for quickly and easily securing wheelchairs in mass transit vehicles. However, a recognized problem in accommodating such mobility aids in buses, train cars, and the like, is the need for reliably securing the mobility aid to prevent its unwanted movement while the vehicle is in motion.
It is desirable in mass transit vehicles to have mobility aid securement systems which are versatile, i.e., that may be positioned so as not to interfere with the use of the vehicle by ambulatory passengers. Preferably, wheelchair restraint systems should be readily stowable so as not to present any obstacle, intrusion or tripping hazard when the restraint systems are not in use. It is also desirable that such systems be readily convertible so that they may be integrated with conventional seating systems in such a way that conventional seating systems may still be used when the wheelchair restraint systems are not needed. It is also desirable to have the restraint systems physically retracted or stowed so as not to present any undue hazard to other passengers when the wheelchair restraint system is not in use.
At the same time, a wheelchair restraint system should be readily accessible to the wheelchair-using passenger, and operable by the vehicle operator, or by the passenger without the need for the assistance of the vehicle driver or any other party. Further, a wheelchair restraint system should be convenient for use, preferably allowing one-handed operation. Preferably, during the positioning and securement of a wheelchair in the vehicle, various elements of the restraint system should be readily manipulatible without the requirements for complex movements, such as the activation of a release with one hand and the activation of a portion of the restraint with the other.
To accomplish these goals, a number of prior art devices have been suggested and, in some cases, developed.
One such class of systems is disclosed by Gresham in U.S. Pat. No. 4,886,403. The system therein disclosed utilizes a plurality of floor-mounted tracks to which are releasably attached one or more seat belts and one or more ratcheting spool assemblies. While this type of system provides some measure of safety to the wheelchair occupant, these systems are difficult to use for a number of reasons. First, the belt assemblies are separate and must be retrieved and appropriately located in and secured to the track and to the wheelchair, and they must be manually tensioned by operation of a ratchet handle or crank.
A more desirable system is disclosed by Kiernan, et al., in U.S. Pat. No. 6,776,564, in which a plurality of belt retractor assemblies are permanently secured to the four corners of a wheelchair station, eliminating the requirement for retrieval and mounting of portions of the restraint system. However, each belt assembly is separate and separately operable, requiring the assistance of an operator. Similar limitations are found in the operation of systems such as that taught by Kraft in U.S. Pat. No. 6,428,254 and Ditch, U.S. Pat. No. 5,888,038.
A somewhat better approach is disclosed by Magnuson, et al., in U.S. Pat. No. 6,524,039, which discloses the use of a pair of retractor assemblies which can be controlled by a common actuator. However, this invention suffers from one of the limitations of the previously described prior art, in that it uses separate exposed retractor bodies which can easily snag or catch other passengers in the vehicle. Further, Magnuson, et al. relies upon a complicated system of cables for interconnecting the remote actuator to the retractors, which is expensive, complicated to install and maintain, and unreliable after repeated use.
All of the prior art systems, however, are limited in that they require the simultaneous activation of a control, usually to release a belt retractor, coupled with movement of the belt to a securing position on a wheelchair. Once the belt has been secured to the wheelchair, the release mechanism may need to again be activated to effect locking. In Magnuson, for example, a release lever is operated with one hand, while the operator extends belts from the retractor with the other hand. Then, once the belts are attached to the wheelchair, the operator releases a lock allowing the belts to retract.
The present system, however, contemplates a timed release mechanism which allows the spools of the retractor mechanism to be freely extended and retracted for a predetermined time interval after actuation of a mechanical or electromechanical control. This system allows for single-handed operation, thereby greatly simplifying the securement and removal of the restraint system from a wheelchair.